Fabric expanding device for weaving machines

ABSTRACT

A device for expanding fabrics on weaving machines. The device comprises an expanding rod which partially extends into a groove provided in a bar which spans the side frames of the weaving machine. The expanding rod is held in its position by means of a system of arms and brackets attached to a supporting bar which is adjustably mounted above the bar. Nearer to its center the rod is provided with threads of opposite hand whereas at its ends it is provided with rotatable pinned fabric engaging rings mounted on rotatably adjustable bushings.

United States Patent Horn et al. Nov. 13, 1973 FABRIC EXPANDING DEVICEFOR [56] References Cited WEAVING MACHINES UNITED STATES PATENTS [75] Inventors: Vladimir Horn, Brno; Vladimir 3,446,250 5/1969 Pfarrwaller 139/294 Kuda, Blazovice; Jindrich Cerny, Brno, all Of Czechoslovakia Primary Examiner-l-lenry S. Jaudon [73] Assignee: Vyzkumny a vyvojovy ustav Zavodu Attorney-Arthur Klem vseobecneho Strojirenstvi, Brno, Switzerland ABSTRACT [22] Filed: May 8 1972 A device for expanding fabrics on weaving machines.

The device comprises an expanding rod which par- PP Nod 251,172 tially extends into a groove provided in a bar which spans the side frames of the weaving machine. The ex- 30 F i A u ti P i it D t panding rod is held in its position by means of a sys- 1 M pp cg on r y a a tern of arms and brackets attached to a supporting bar 3y Czechoslovakia is jus ab y ou e above the bar Nearer to its center the rod is provided with threads of opposite hand whereas at its ends it is provided with rotatable I I n 0 u I n a 1 e I l a e n e e e u e v A I l l e e I e u 1 I I a I l l a l [58] Field of Search 139/293-299 justable bushings.

5 Claims, 3 Drawing Figures 1 FABRIC EXPANDING DEVICE FOR WEAVING MACHINES The present invention relates to a device for expanding a fabric from the center of the fabric towards the selvedges thereof downstream of the binding point of a weaving machine.

The hitherto known fabric expanding devices comprise pinned rings rotatably mounted on mandrels, the latter being attached to the machine frame, the rings engaging the selvedge portions of the fabric. The number of the rings, their size and inclination of their axes of rotation are different, depending on both the kind of the fabric and the type of the machine.

There are also known the so-called full-width temples which usually consist of two bars disposed across the whole width of the weaving machine and provided between the two bars with a longitudinal groove in which a rod having circular cross-section is located. The fabric which partially encircles said rod urges the latter, under its pressure, against the two bars, whereby the fabric is clamped and kept within the range of the width of the drawn-in'reed.

A disadvantage of the device operating with the pinned rings resides in the damaging of the fabric fabric; at its selvedges by the action of the needles which have to overcome a relatively large tension in the fabric; this also results in a rapid wear of the pinned rings.

A drawback of the known full-width temples is their low efficiency, particularly at the selvedges of the fabric. This results in uneven beat-up stripes which increase towards the selvedges. Thereby the warp threads are loosened and an increased rate of breakage of the latter occurs, particularly with fabrics having a higher warp set.

A disadvantage common to the two types of the temples described hereinbefore is the difficult access to the fabric selvedges and, additionally, with the full-width temple, difficult handling of the warp and the fabric due to their clamping in the temple.

The above-mentioned disadvantages and drawbacks are eliminated by the subject matter of the present invention wherein an expanding rod extends partially into a groove provided in a bar which is fixedly connected with the side frames of the weaving machine, the expanding rod being held in its position by means of a system of arms and brackets attached to a supporting bar which is adjustably mounted in the side frames above the bar and is provided nearer to its center with threads whereas at its ends it is provided with rotatable pinned rings mounted on rotatably adjustable bushings. The length of the bar at the point of the groove and the length of the expanding rod, including the brackets, does not exceed the width of the fabric at the drawn-in reed.

The advantage of the device according to the invention resides in its high efficiency throughout the fabric width, which enhances both the uniformity and the quality of the fabric over its entire width. This fact offers further advantages, such as uniform tension in all warp threads whereby the breakage rate thereof is reduced.

Another advantage resides in a substantially improved quality of the fabric selvedge portions engaged by the pinned rings, since the needles of the rings are subjected to considerably lower forces produced by the tension in the fabric. Therefore, the service life of the rings is also increased.

A no less important advantage resides in an easier handling of both the warp and the fabric.

An exemplary embodiment of the device according to the invention is diagrammatically shown in the drawings, in which:

FIG. 1 is a plan view of the device in a weaving machine; I

FIG. 2 is a section through the device taken on the line II-II in FIG. 1; and

FIG. 3 is a section taken through the device on th line III-III in FIG. 1.

Turning now to FIG. 1, between side frames 1 and 2 of the weaving machine, under the weaving plate, a bar 3 is fixedly mounted, along the whole length of which a groove 4 is provided and oriented in the direction transverse to the direction of travel of fabric 5, the central part of which is omitted. An expanding rod 6 extends partially into the groove 4, the rod 6 being fixedly attached in the exemplary embodiment by means of screws 7 to a system of arms 8. The arms 8 are fixedly mounted on a supporting bar 9 which is adjustable mounted by journals 10 in the side frames 1 and 2 of the weaving machine as shown in FIG. 1. The surface of the expanding rod 6 is provided with threads 11 and 12 of opposite hand extending from the center of the fabric 5 towards the two sides thereof, the left-hand portion of the expanding rod 6 having a right-hand thread 11, whereas the right-hand portion of the expanding rod has a left-hand thread 12. Fitted over the two ends of the expanding rod 6 are bushings 13 (FIG. 2) on which each of there are rotatably a plurality of mounted skew oriented rings 14 provided with projecting pins (pinned). The distance between the last two pinned rings 14 on the two ends of the expanding bar 6 is always adjusted in such a way so as to be identical with the width of the fabric 5 at the reed. Also the length of the groove 4 in the bar 3 equals such width of the fabric.

The central bushings 13 which carry the pinned rings 14 are preferably rotatably adjustable mounted in halfround jaws 15 of brackets 16 (FIG. 2), the latter being fixedly mounted on the supporting bar 9. Free rotation of the bushings 13 is prevented by jaws 17 with screws 18 which are screwed in the brackets 16.

The temple operates as follows:

The fabric 5, produced in a known manner, advances from the binding point towards the temple device of the invention; in such path it passes above the bar 3, where it is urged by the expanding rod 6 into the groove 4 in the bar 3 so that the expanding rod 6 is partially encircled by the fabric. Thus the fabric 5 is engaged by the threads 11 and 12 and, due to the incline of the latter, the central portion of the fabric 5 is expanded. At the same time, the selvedge portions of the fabric 5 are engaged by the pinned rings 14, where, due to the rotation of said rings in an inclined plane, the fabric 5, now already at the full width of its wrap threads as drawn into the reed, is still further expanded.

When it is desired to change the rate of expansion of the fabric 5 the supporting bar 9 may be turned, for example manually, in such a manner that the expanding rod 6, with its threads 11 and 12 and the pinned rings 14, is depressed to a greater or lesser degree into the groove 4 of the bar 3, whereby the angular extent of engagement of the fabric 5 with the expanding rod 6 is selectively increased or reduced. After adjustment, the

supporting bar 9 is secured in the side frames, for example, by screws (not shown).

With the device it is also possible to carry out individual adjustments of the pinned rings 14 as follows: Screws 10 are loosened, whereby jaws 17 are released. Thereafter the bushings 13 with the pinned rings 14 are turned to the required position, and, by tightening the screws 18, the bushings 13 are again clamped between the half-round jaws l5 and the jaws 17 in the brackets 16.

The invention may be utilized in various types of weaving machines.

Although the invention is illustrated and described with reference to one preferred embodiment thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a preferred embodiment, but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

1. A device for expanding woven fabrics on weaving machines, comprising an expanding rod, the expanding rod partially extending into a groove provided in a bar which spans and is fixedly connected with side frames of the weaving machine, the woven fabric passing around the portion of the rod in the groove, the expanding rod being provided adjacent its center with threads of opposite hand, and at its ends being provided with rotatable pinned rings.

2. A device according to claim 1, wherein the expanding rod is held in its position by means of a system of arms and brackets.

3. A device according to claim 2, wherein the system of arms and brackets is attached to a supporting bar which is adjustably mounted above the grooved bar in the side frames of the weaving machine.

4. A device according to claim 1, wherein the pinned rings are mounted on rotatably adjustable bushings.

5. A device according to claim 1, wherein the length of the grooved bar and the length of the expanding rod including the brackets substantially equals the drawn-in reed width of the woven fabric. 

1. A device for expanding woven fabrics on weaving machines, comprising an expanding rod, the expanding rod partially extending into a groove provided in a bar which spans and is fixedly connected with side frames of the weaving machine, the woven fabric passing around the portion of the rod in the groove, the expanding rod being provided adjacent its center with threads of opposite hand, and at its ends being provided with rotatable pinned rings.
 2. A device according to claim 1, wherein the expanding rod is held in its position by means of a system of arms and brackets.
 3. A device according to claim 2, wherein the system of arms and brackets is attached to a supporting bar which is adjustably mounted above the grooved bar in the side frames of the weaving machine.
 4. A device according to claim 1, wherein the pinned rings are mounted on rotatably adjustable bushings.
 5. A device according to claim 1, wherein the length of the grooved bar and the length of the expanding rod including the brackets substantially equals the drawn-in reed width of the woven fabric. 